Conventionally, film formation of a recording layer, reflective film and the like on the resin substrate of a disc-shaped recording medium, for instance, has been performed by sputtering film formation.    [Patent Citation 1]    JP-A 5-311425 (1993)    [Patent Citation 2]    JP-A 5-179426 (1993)    [Patent Citation 3]    JP-A 11-144338 (1999)